This invention relates to a cross-country vehicle or machine with a superstructure arranged on the chassis of the vehicle or machine in the form of for instance a driver's cab, crane and/or one or more other working tools.
On machines such as forest machines provided with a driver's cab, this is normally rigidly connected to the chassis, of the machine and follows in this way the movements of the chassis slavishly always arising upon passage over obstacles on the ground. These movements can be very great and violent sideways as well as forwards and backwards, and do not promote the driver's working conditions within his cab, but sooner the contrary.
The rigid mounting of the driver's cab relative to the chassis has also the disadvantage that the cab is inclined in one direction or the other as soon as the machine is stopped on non-horizontal ground for work, and this circumstance is very troublesome for the driver, especially in machines of the excavator type, where the driver's cab, together with the working tool, is pivotable by means of a roller path around a vertical shaft relative to the chassis. This type of machine must as a rule, have a horizontal ground to operate in the intended way and in order not to be exposed to too great stresses.
In order to overcome this problem and to attain better working conditions for the driver, attempts have been made with gyro-suspended driver's seats and with various types of hydraulically-operated systems with swing arms and axles, enabling a certain adjustment of the wheels of the machine relative to the chassis. However, these systems are relatively complicated and expensive.